A concise assessment of the risks to human health posed by exposure to azodicarbonamide, a chemical mainly used as a blowing agent in the rubber and plastics industries. The compound is used in the expansion of a wide range of polymers, including polyvinyl chloride, polyolefins, and natural and synthetic rubbers.
Although no data on environmental levels are available, the report cites limited evidence suggesting rapid biodegradation in soil. Azodicarbonamide released to surface waters is expected to partition to the hydrosphere with no signification sorption to particulates. No data on exposure of the general population could be identified. Concerning kinetics and metabolism, limited animal studies of exposures via inhalation and ingestion indicate that substantial quantities remain unabsorbed and are rapidly eliminated in the faeces. Studies further suggest that most systemic exposure is to the breakdown product, biurea, and not to the parent compound.
Toxicity studies conducted in experimental mammals demonstrate low acute toxicity and no irritation of skin, eye, or respiratory tract. Although azodicarbonamide was found to be a mutagen in bacterial systems, the report found no evidence that this effect would occur in vivo. No adequate studies of carcinogenicity and reproductive toxicity, in animals or in humans, could be identified. Case reports and epidemiological studies in humans have produced abundant evidence that azodicarbonamide can induce asthma, other respiratory symptoms, and skin sensitization in exposed workers. Adverse effects on other systems have not been studied.